Method of exploring operating structures



C. H. SCHLESMAN METHOD 0F EXPLORING OPERATING STRUCTURES Filed sept. 14', 1940 sheets-sheet 1 @ggf /Mlfsaffweifagslf j A O RNEY Y Y C. H. SCHLESMAN METHOD OF EXPLORING OPERATING STRUCTURES Apnl e, 1943.

Filed sept. 14', 1940 2 sheets-sheet 2y Patented Apr. 6, 1943 UNITED STATE METHOD OF EXPLORING OPERATING STRUCTURES Carleton H. S'chlesman, Camden, N.

Socony-Vacuum Oil Company,

J., assigner to Incorporated,

New York, N. Y., a corporation of New York Application September 14, '1940, Serial No. 356,781

2 Claims,

This invention deals with a means oi con trolling the operation of certain types oi equipment, supplies means of trouble shooting in production equipment without interruption to pro-` duction, supplies a method of studying the operation o! pilot plants and in detecting irregularities in material handling systems, including pipe lines, where conditions of pressure, temperature, location or necessity of continuous operation make ready access to or the frequent disassembll1 of equipment impossible. f

The device here disclosed finds most ready use as a maintenance tool in connection with the operation of catalytic conversion equipment. In constructing plants for the conversion of chemical materials or petroleum products by catalytic means, such as in the Houdry cracking operation, it becomes necessary to provide the catalyst mass with a complex system of conduits or iin pipes for the purpose of distributing throughout the catalyst mass the material being processed, and air or other materials required for regeneration. Other tubes are provided for circulation of liquid medium for the removal or introduction of heat to the catalyst mass.

It will be appreciated that the maintenance of so complicated a mechanical system is a dif- Dilcult task. For example, when it becomes necessary to replace the catalyst mass-which is frequently accomplished by blowing the catalyst pellets from the case by means of compressed air-difficulty is sometimes experienced with a hanging up of isolated masses of catalyst whose location is unknown.

As a converter of the type described consists of a labyrinth of steel tubing and iins, it will be appreciated that a measuring instrument which can be operated within the case during maintenance operations, or during inspection periods without dismembering the case will be of particular value. So far as we know, no measuring equipment of this type has been described by others.

The device here disclosed is also capable oi being utilized for the study of the flow of materials through continuously operating processes. for example long rotary kilns, such as are used in the manufacture of Portland cemen and other processes wherein either fluids, solids, or semi-solids flow through either step by step processing or branched iiow processing where usual conditions of volume ilow study are difilcult to obtain.

This invention has for its object the proviktive materials, to operation as an and device to quantitative sion of method and means whereby extensive exploration of complicated piped structures can be accomplished without dismantling. A similar major object is the provision of means whereby study of flow conditions may be made in ramiiied processes and processes not readily adapted to ordinary means of study.

The present method and device is based upon the idea of placing a source of radiant energy within the equipment under study and determining its location or the like by detection of the emanations. Former devices of this general type exist, but are open to the objection that they are not adaptable. as is the present method measurements oi p0- of obstrucunattended signalling device, to observation of results from a distance, and of considerable importance, to study of flow conditions within a highly ramied system.

The device used in parts:

(1) An indicator capable of emitting penetrating radiation. In the case of a tube in a catalyst case, for example, a small amount of radioactive mineral enclosed in a suitable cap-` sule may be lowered into it and subsequently recovered; or, in the case of a rotary kiln, material such as pitch blend, which is capable of emitting rays capable of penetrating the wall ci the kiln, may be introduced into the kiln in the form of a powder. In other cases, an electronic or cathode beam device such as, for example, a source of X-rays might be utilized.

(2) One or more detector heads. These are sition, to quantitative measurements the invention involves three devices which originate weak-signal currents,-

etc., which are a function of the intensity oi' the radiation being received. These may consist of small gas-lled glass tubes containing suitable electrodes such as, for example, are used in Geiger Mueller counters. The tube may be enclosed in a bakelite tube, etc., to permit forcing into a packed mass of catalystror may be enclosed in similar protection vfor permanent installations; suchy detector units to be connected to the receiving and indicator units by one or more cables. In some cases it may be advantageous to attach tube, which is attached to the main amplifier and the batteries by a iiexible cable of the desired length.

(3) An indicating or ecording device which ampliiles the weak impulses received from the a preamplifier to the counter v trated as follows:

detector, selects desired signals and rejects s ous signals such as cosmic rays when so desired, and integrates the signal to give the indicating or recording element the desired scale characteristics such as linear, logarithmic. etc.-

The operation of the invention may be illus- In one commercial type of catvertical tubes are provided for the introduction of the vapor to be passed into the catalyst. Other vertical tubes are provided for the circulation of heat transfer media, and a third set for the introduction of air or other gases when it becomes necessary to regenerate the catalyst. The` catalyst, in pellet form, is placed between these vertical tubes. Assuming that during inspection of the unit, it becomes desirable to discover voids in the catalyst mass. this may be accomplished by lowering into one of the tubes-for example, the vapor tube-a device capable of emitting penetrating radiation which will pass through the walls of the tubes, penetrating the catalyst mass, and which may then be detected by lowering a suitable detector in another tube parallel to the iirst.

`It will be appreciated that if the source of radiation and the detector head are passed at equal rates through the adjacent tubes within the catalyst mass, so that both units are continuously at a xed distance from each other, the presence or absence of catalyst in the space between the tubes can be determined from the indications of the meter operated by the detector head. Since the catalyst mass will impose considerable resistance to the penetration of the radiation, voids in the catalyst mass should be indicated by an increase in the meter reading, while fusion of catalyst at any point would be indicated by a decrease in the meter reading because of the higher density and, hence, increased resistance to radiation of the catalyst at that Point.

If it is simply a question of locating a partial obstruction in a tube or pipe, for example, a plug containing a small amount of` radioactive mineral is forced through the line until it reaches the obstruction. The progress of the plug is followed with a portable detector and indicator having a linear scale. In addition, a contact may be placed on the meter to show a red light when the plug is within a short distance of the detector. 4When the obstruction is reached, the

alytic converter,

tube is marked and scale readings taken at several points on either side of the obstruction. The plug will be found midway between points giving equal scale readings.

When ow through a kiln o r branching lines is being studied, or the amount of loss oi' fluids or solids from leak is being estimated, material may be introduced into the unit in suillcient quantity in the charge to give a full scale reading when the detector element is in contact with the line. This may be facilitated by providing a meter sensitivity adjustment on the instrument. The meter, if pronerlv calibrated, would then read percentage of total flow passing some other point in the line. l

The previous examples serve to indicate the manner in which the invention may be employed. 'Ihe following description represents the preferred form of apparatus, and alternate forms which may be employed to advantage:

(l) Source of radiation- The preferred source of radiation appears to be a radio active mineral such as pitch blend which, for convenience in handling, is mounted in a jacket tted with lugs for the attachment of wires or rods for positioning in the tubing being investigated..

A second source, which appears to be particularly attractive for.routine inspection of steel tubing for ilaws or in other specialapplications, is a small X-ray tube having a target which will produce a concentrated beam-electrical energy being supplied to the tube by means of insulated cable.

(2) Detector head-The type of detector head will, of course, vary with the character and intensity of radiation employed. -The preferred form appears to be a compact electrode unit of the gas-filled type such as a glass-enclosed Geiger Muller counter, which is enclosed, together with a preliminary electronic amplifier tube in a thin protective shell, which is also fitted with. lugs for positioning during use. 'I'he detector unit is connected to the indicating apparatus by one or more cables.

(3) Ampli/ying and indicating equipment-An indicating or recording device which amplifles the weak impulses received from the detector, selects desired signals and rejects spurious signals such as cosmic rays when so desired, and integrates the signal to give the indicating or recording element the desired scale characteristics such as linear, logarithmic, etc. In general, this equipment will consist of a vacuum tube amplier connected to a vacuum tube volt-meter.

The manner in which the equipment is utilized is illustrated by Figure 1. This serves to show the method followed in the location of a fused mass of catalyst within a catalyst case from which the main body oi' catalyst has been withdrawn.

The source of radiation I, consists in this case of a small capsule containing radium which is enclosed in a bakelite protecting jacket and is attached to the end of a long straight measuring rod 5. 'I'he source is lowered into the catalyst case through any convenient one of the heat exchange tubes. The rod is provided With reference marks 6 which serve to indicate to the operator the level and the source of radiation. The detector 'i which consists o! a gas-filled tube and a primary amplifier mounted within a light weight enclosing case is attached to a long tube also provided with reference marks. Power is supplied to this unit by means oi' a iiexible cable passing through the tube and connecting with the amplier and power supply 8.

The arrangement of the electrical equipment is shown in a diagrammatic sketch in Figure 2. In operation, the source of radiation and the d'etector head are loweredthrough the case at a constant rate in such a manner that both remain in the same geometrical relation. this operation, the operator notes the position o1' the indicating meter which may be iltted with an alarm or may be equipped to record. This indicator shows continuously the amount of radiation reaching the detector head from the source.

If as the equipment' is lowered obstructions are encountered, such as, for example, a fused mass of catalyst, the reading of the indicator-Will immediately fall oil' allowing the operator to estimate the size of the obstruction. The extent of the obstruction can be calculated by taking readings at several levels or between various adjoining tubes.

The operation of the electrical equipment can be explained somewhat as follows: A source of radiation, such as, for example. radium is continually giving oir penetrating rays. (Referring opening or through now to Figure 2,), 'these rays penetrate through the glass wall of the detector head 9 which may consist of a gas-filled tube charged to a high electrical potential and are capable of initiating a discharge between the outer jacket and the inner electrode through ionization of the gas. The occurrence of such momentary discharge causes a -pulsating flow of current which alternately lowers and raises the grid potential of the vacuum tube Il). This potential change is ampliiied by the tube and transmitted through a shielded cable to the amplifier feed which also contains the main power supply. After further amplication by vacuum tube Il the pulsating current is rectied by means of vacuum tube I2. The rectified current so obtained is fed to indicating meter I3 through a resistance capacitance circuit capable of averaging the pulses for the purpose of obtaining a steady meter reading.

If, when a large and very dense mass of material is interposed between the source and the detector head, the meter is adjusted to read zero and meter reading of 100 may be obtained by the aid of .adjustment of the amplifier While the source is separated from the detector only by air. Under these conditions,V subsequent meter readings will serve to indicate the amount of any dense foreign material interposed between the source and the detector head. This is the principle which is employed in indicating voids and obstructions in catalyst cases and similar equipment;

To show operation for determining the position of `obstructions in a pipe, the same set up is again shown in Figure 3, with like indicia, except that in this case the detector 1 of Figures 1 and 2 is shown in divided form, with the detector h ead 9 movable independently of the ampliiier I0.

When studying flow conditions wherein a radioactive pellet is allowed to pass through a system in the material owing therein, detectors may be placed at fixed locations. When studying ramied iiow conditions when radioactive material is admixed with the flowing material and study is by measuring its concentration at var' ious points, fixed detectors may again be used.

1. Method for the exploration of rarnifled structures comprising moving a source of radiant energy through portions of said structure in maintained geometric relationship with a detector moved through other portions of said structure which detector is capable of translating incident radiant energy into proportional electrical energy, amplifying electrical energy so generated to desirable signal strength, measuring the proportional amount of electrical energy so gener'- ated, and determining conditions between the source of radiantl energy and the detector by analyzing iiuctuations in the amount of radiant energy translated between said source and said detector. l

2. Method for determining the position of an obstruction in a ramified tubular structure through which fluids are passed comprising introducing a carrier 4containing a source of radiant energy thereinto to be carried by said fluids until lodged against the obstruction, placing a detector of radiant energy successively at each of a series of points Whose exact location with respect to the ramified structure is known, .the detector being capable of translating incident radiant energy into proportionate electrical energy, measuring such proportionate energy for each'location vof the detector, and from the varations in signal strength between successive 1ocations determining the previously unknown po-L sition of the obstruction with relation to the known character of the structure.

CARLETON H. SCHLESMAN. 

